Microbes are tiny, single-celled organisms that can live in almost any environment. They include bacteria, viruses, fungi, algae and protozoa. Some microbes are useful, or even good for your health: foods like yogurt, sauerkraut and cheese are all made using bacteria. But a small percentage -- less than 1 percent -- can cause diseases in humans.
Antimicrobials are substances that kill or inhibit the growth of bacteria, yeasts, and molds. They can occur naturally or be manmade synthetic compounds.
- Organic acids and their salts are the most common antimicrobial materials.
- Potassium sorbate is used to package cheese. It absorbs oxygen within the package, preventing the growth of mold, which depends on oxygen to flourish.
- Gas enriched with sulfite can prevent or delay the development of fungus.
- Tetracycline is an antimicrobial that enters the harmful bacterial cell and stops it from making new proteins. Without those proteins, the bacterial cell cannot divide and multiply.
- Other antimicrobials kill bacteria, while penicillin stops new cell walls from developing.
Many antimicrobials can be used directly in food packaging and will diffuse into the food.
Microbes are evolving to develop resistance to drug treatments that were once effective in combating them. Medicines that attack harmful bacteria may also attack helpful bacteria as well, and may also become resistant. We depend on antimicrobials for our health, but the more we use them, the more bacteria may become resistant to them.